Gas transmission pipelines are susceptible to both internal (gas side) and external (soil side) corrosion attack. Internal corrosion is caused by the presence of salt laden moisture. (O, H and perhaps O in the natural gas). Internal corrosion usually manifests itself as geiieral corrosion. However the presence of chlorides in entrained water also can lead to pitting corrosion damage. The immersion technique can differentiate general from localized corrosion and provide estimate for corrosion rates without external perturbation and the corroding system. In this project, this involves the immersion of carbon steel in these expose location. The specimens are fixed at three different locations. The exposure time vary between 30, 60, 90, 120, 150 and 180 days. From this study the corrosion behaviour of carbon steel have been evaluated based on exposure location.